Process of preparing plastic molding material



25 tic condition suitable for molding purposes I UNITED STATES PATENTOFFICE.

OSCAR GERLACH, OF AND CH RISTIAN IB. LIHME, OF CHICAGO, ILLINOIS,ASSIGNORS TO THE INDUSTRIAL RESEARCH 'LABORATORIES,. A CORPORATION OFSpecification of Letters Patent. Patented Sept. 13,1921.

ILLINOIS.

PROCESS OF PREPARING PLASTIC MOLDING MATERIAL.

No Drawing.

nois, and the city of Chicago, county of.

-Cook, .and State of Illinois, respectively,

have invented certain new and useful Improvements in a Process ofPreparing Plastic Molding Material; and we do hereby de clare that thefollowing is a full, clear, and exact description of the same.

7, This invention has reference to a process for treating or supplyingdesirable properties to plastic materials, such as clay, that are to bemolded or shapedin a plastic conditioni The object of this invention isto reduce the mass of molding material toa condition wherein it issuitable for facile molding, such condition being obtained by a processthat is rapid and-inexpensive.

Another object of this invention is td reduce the mass of moldingmaterial to a plasby the introduction or mixing therewith of anelementwhich gives suitable plasticity to the mass.

Another object of this invention is to combine a sulfite liquor with amass of molding a material to give plasticity to, the mass.

Another ect of the invention is to provide a lastic molding materialwith qualities which will prevent adhesion of the plastic material toparts of the molding apparahis and prevent breaking and tearing of thelastic material durin the process of moldmg the plastic material intoits form.

Another object of the invention is to provide the necessary lubricationfor the plastic material to prevent tearing or breakingof the moldingapparatus, such lubrication beor other similar machine. The claycomposition is then kneaded in a'wet condition, and in order to obtainthe proper plasticity,

Application filed December 15, 1917. Serial No. 207,219.

the clay composition, after kneading, is maintained in a damp conditionfor a considerable period of time and thereby aged, before being moldedin its final shape. This aging not only consumes considerable time, butis a somewhat delicate process that requires considerable attention andcare.

Our invention is designed to obviate this somewhatv long process ofaging, and to reduce the mass; of clay quickly to the desired state ofplasticity for molding, and consists in introducinginto the massprevious to the molding, a sulfite liquor which is a by-prodnot of pulpmanufacture. This sulfite liquor, which results from pulpmanufactu're,is of little commercial value, and by using it for the purpose of givingthe molding material its plasticity, we not only provide a process whichtakes very little time, but we are also able to reduce the moldingmaterial to the desired condition of plasticity with a ratherinexpensive ingredient. The amount of sulfite liquor required may bereadily determined by adding the liquor, to the mass, and

kneading it therewith until the mass 'as-' sumes the desired plasticity.

As an additional step in the complete preparation of the moldingmaterial for the In the manufacture of retorts or similar vessels, wheredensity of material is r uired,

it is the practice to mold the vessels y the use of a plunger, and forcethe clay from a hopper into the mold. Where the clay enters the mold,there is a tendency of the clay to parts of the molding apparatus, andto prevent this trouble, the mold is generally greased with some form ofoil to prevent the plastic material as t is operated on by i f oadhesion.

We have found that a small quantity of tear, due to adhesion of theplastic clay to" petroleum coke ground and, thoroughly mixed with theclay mass, furnishes the desiredlubrication, and reven't'sadhesion andbreaking or tearing o the clay which is ex perienced when a lubricant isnot used.

course, the sulfite and petroleum coke may be introduced at any stage ofthe preparation of the mass previous to actual molding.

It is obvious that details of our process.

maybe changed or varied, and we do not purpose limiting the patentotherwise than necessitated by the prior art.

\Ve claim as our invention:

1. The process of aging materials to be used for molding purposes whichcomprises mixing with the material an acid solution containing sultiteliquor which acts immediately to impart to the material a plasticitysuch as obtained by allowing the material to stand in a damp conditionfor a long period ot'time.

2. The process of preparing material for molding purposes which consistsin reducing the molding material to a IJltlStlCCOIldltlOIl.

adhesive material to prevent adhesion to the molds.

3 The process of preparing material for molding purposes which consistsin reducing the molding material to a plastic condition, and mixingtherewith a small quantity of pulverized petroleum coke and forming thematerial in an unheated mold.

In testimony whereof we have hereunto subscribed our names in thepresence of two subscribing witnesses.

OSCAR GERLACH. CHRISTIAN B. LIHME. Witnesses EARL M. HAnmNn, CHAnLEs W.HILLS, Jr.

